Ultrafast proton radiography has been frequently used for direct measurement of the electromagnetic fields around laser-driven capacitor-coil targets. The goal is to accurately infer the coil currents and their magnetic field generation for a robust magnetic field source that can lead to many applications. The technique often involves numerical calculations for synthetic proton images to reproduce experimental measurements. While electromagnetic fields are the primary source for proton deflections around the capacitor coils, stopping power and small angle deflection can also contribute to the observed experimental features. Here we present a comprehensive study of the proton radiography technique including all sources of proton deflections as a function of coil shapes, current magnitudes, and proton energies. Good agreements were achieved between experimental data and numerical calculations that include both the stopping power and small angle deflections, particularly when the induced coil currents were small.
超快质子照相技术已被频繁用于直接测量激光驱动电容器-线圈靶周围的电磁场。其目标在于精确推断线圈电流及其磁场产生机制，以构建一个稳健的磁场源，从而推动众多应用的发展。该技术通常涉及数值计算，以生成合成质子图像，用于复现实验测量结果。尽管电磁场是导致质子围绕电容器-线圈靶偏转的主要因素，但阻止能和小角散射也可能对观测到的实验特征有所贡献。本文对质子照相技术进行了综合研究，涵盖了作为线圈形状、电流幅度和质子能量函数的全部质子偏转来源。实验数据与包含阻止能和小角散射效应的数值计算结果取得了良好的一致性，尤其是在感应线圈电流较小的情况下。